... of As, Se, Sb, Bi, Pb, Sn, Te, Ge, In, Model GD320N Atomic Absorption SpectrophotometerCharacteristics A Build-in computer data processing ... limit of copper: ≤0.008mg/mlBackground calibration ability: Greater than 30 times.Standby Interface: RS 232 Instrument power supply: 220V, 3A ... are available.Software with I/O portPrinterOverall dimension & weight: Model GD320N Atomic Absorption Spectrophotometer